California’s longest-running single-issue political battle, over limits on damages in medical malpractice lawsuits, is about to heat up again.

Personal injury attorney Nick Rowley, who says his infant son’s lungs were “blown up” by medical malpractice, and Consumer Watchdog are proposing a 2020 ballot measure that would largely nullify California’s Medical Injury Compensation Reform Act (MICRA) that limits “pain and suffering” compensation to $250,000.

In 1975, the Legislature and Jerry Brown, then in the first months of his first term as governor, enacted MICRA to cope with what medical providers said was a crisis caused by outlandish damages in malpractice cases.

The providers, saying that they were becoming uninsurable due to the rising awards, had mounted an all-out campaign for relief — including even a sleep-in by doctors’ wives in Brown’s outer office.

The campaign overwhelmed opposition from the California Trial Lawyers Association, which later renamed itself Consumer Attorneys of California. One MICRA provision clamped tight limits on contingency fees lawyers could receive in malpractice cases, making them unprofitable.

As soon as MICRA was enacted, the lawyers embarked on what became a 44-year-long drive to undo it, either in the Legislature or by ballot measure, but suffered defeat after defeat at the hands of Californians Allied for Patient Protection (CAPP), the medical industry’s pro-MICRA coalition.

The only significant change in MICRA came in 1987, when a slight loosening of the contingency fee limits was written into the infamous “napkin deal” on personal injury liability issues hammered out late one night in Frank Fat’s restaurant in Sacramento.

The most recent clash was Proposition 46, a 2014 ballot measure backed by Consumer Watchdog and personal injury attorneys that would have more than quadrupled the $250,000 cap on pain and suffering damages. The proponents spent more than $12 million on the campaign but medical providers and insurers spent five times as much and the measure was rejected by an overwhelming 2-1 margin.

The new proposal would technically leave a cap on damages in place, but raise it by inflation since 1975, thus pushing it over $1 million, adjust it for inflation in the future, allow the cap to be pierced for “catastrophic injuries,” and increase lawyers’ contingency fees for winning. The proposed measure would also allow juries in malpractice cases to be informed of the cap, something prohibited by MICRA.

A 2020 clash would be pretty much a repeat of Proposition 46.

Proponents would contend that inflation has eroded the $250,000 cap to practically nothing and cite multiple instances of patients being horrendously damaged by sloppy medical procedures but receiving little or no compensation.

Opponents would portray it as an effort by greedy lawyers to fatten their bank accounts and in doing so, drive up the cost of medical care to patients and insurers.

But will it come to another showdown at the polls?

The measure’s backers clearly hope that a massive turnout of anti-Donald Trump California voters next year would offer a much more receptive atmosphere than the non-presidential election of 2014, which had a record low voter turnout.

Were they to qualify their measure and polling showed it had a fair chance of winning, medical providers and insurers might be willing to compromise and forestall another all-out ballot measure war.

That possibility exists because of a relatively new law allowing proponents of ballot measures to drop them even after they qualify for the ballot, thus enhancing leverage for dealmaking.

Without a deal, the medical industry will, as it has done in the past, spend lavishly to defeat a MICRA overhaul, because the potential stakes are billions of dollars.